My house is a bi-level, not a true two story. There are two rooms to choose from. One is much larger and downstairs and the other is what was considered the Master Bedroom when the house was built. This second room is upstairs.
I have two dogs - a beagle & a Shitzu. I have another roommate who is a teacher and she lives downstairs. She has two cats and a rabbit. Pets are not a problem.